Air conditioning system



W. J. AULSEBROOK AIR CONDITIONING SYSTEM July 11, 1939.

Filed April 25, 1955 INVENT OR. a BY mjmw Patented July 1 1, 1939 UNITED STATES PATENT OFFICE 2,165,831 4 AIR CONDITIONING SYSTEM William J. Aulsebrook, Evansville, Ind., assignor to Serve], Inc., New York, N. Y., a corporation of Delaware Application April 25, 1935, Serial No. 18,113

14 Claims.

fication and of which:

The figure shows more or less schematically an air conditioning system embodying my invention.

Referring tothe drawing, an air duct, generally indicated by the reference character I0, is constructed to forma main passage I l and a by-pass' passage I2. A suitable fan or blower l3 causes air to be drawn into the inlet end I of the air duct and discharged at the outlet end l5 of the air duct.- Relative flow of air through the main passage II and the by-pass passage I2 is regulated by .a damper l8 of a known type comprising a plurality of shutters'in the by-pass passage l2 and which are operated together by a suitable operating rod II.

In the main passage I l of the air duct I0 is arranged a cooling element l8 of a compression type refrigeration apparatus whichalso includes a mov tor driven compressor l9 and a condenser 20. The

cooling element I8 is shown in the form of a coil having loops extending generally perpendicular to the fiow of air through the passage I l and provided with heat transfer plates or fins extending generally perpendicular to theloops and substantially parallel to the flow of air in the passage H. The refrigeration apparatus contains a suitable cooling fluid which is compressed in the compressor l9, liqueiledin the condenser 28, and evaporated in the cooling i element l8. Compressed refrigerant vapor flows from the compressor l9 through conduit 2| to the condenser 20. Liquefied refrigerant flows from the condenser 20 into a receiver 22. From the receiver companying drawing forming a part of this speci-.

sure side of the refrigeration apparatus. The

pressure or cooling element temperature control switch, not shown. When the damper I6 is fully closed, all of the air drawn through the duct l0 flows through the main air passage l I in thermal exchange relation with the cooling element l8. When the damper l 6 is fully open, air flows through both the main passage II and the by-pass passage l2.in proportions relative to the respective resistances to air flow to these passages. This relative air flow through the passages II and I2 may be varied by moving the damper l6 between its fully open and fully closed positions. For the purpose of operating the damper I8, I provide a device comprising a lever 28 pivoted at 29, an expansible bellows 30 arranged in operative relation with one end of the lever 28, and a load spring 3| which may be adjusted by a screw 32. The damper operating rod II is connected to the longer end of the lever 28 so that the movement of the expansible bellows 38 may be multiplied in operating the damper IS. The expansible bellows 30, is connected by means of a conduit 33 and a conduit 34 to the conduit 23 which is in the high pres- 36 and a similar valve 31 is provided in conduit 35. 30

In the discharge end I5 of the air duct is arranged a three point humidostat 38. The movable contact 39 of the humidostat is connected to one side 40 of an electric circuit. One fixed contact 4| of the humidostat is connected by a conductor 42 to one side of the solenoid which operates the valve 31'. The other fixed contact 43 is connected by a conductor 44 to one side of the solenoid which operates the other valve-38. The other side45 of the electric circuit is connected in common to the other sides of the solenoids which operate valves 36 and 31 by conductor 48 and conductors 41 and 48 respectively.

The humidostat is represented more or less schematically and shows a simple snap-action toggle 50 for imparting quick motion to the contact 39. Under normal conditions, the humidostat contact 39 stands closed against contact 4| so that valve 31 is energized and open and valve 38 is de-energized and closed. The bellows 30 is 50 connected by conduits 33 and 35' to the conduit 24 in the low pressure side of the refrigeration apparatus. The damper IE will assume a position determined by the adjustment of the spring 3] which opposes the action. of the bellows 30 on.

the lever 28. If the pressure in the cooling element l8 rises, tending to deliver air of higher relative humidity at the outlet 15, this rise in pressure will be exerted through bellows to open the damper l6 and thus by-pass a portion of the air, or more of the air, through the passage II. This relief of load on the cooling element I 8 will permit the refrigeration apparatus to lower the temperature of the coil until a balance is again established and air of proper moisture content is delivered from the coil.

It will be understood'that this device will function as an unloader at the time of starting the refrigeration apparatus. In the event that the cooling element i8 has been allowed to become warm during a shut-down, the high pressure in this side of the apparatus at starting will cause the damper it to take a wide open position and thus divert a large portion of the air around the cooling element l3 until the compressor is able to reduce the temperature of cooling element l8 to its normal operating temperature.

. Upon extreme conditions of load, if the normal by-pass regulation of air how in response to low side pressure, as described, fails to maintain the relative humidity of delivered air below a predetermined limit, the humidostat 38 will cause the contact 39 to break from the normal contact ll and close on the contact 43. Thereupon, the valve 36 becomes energized and opens and valve 31 becomes de-energized and closes. When valve 36 opens, high pressure liquid in conduit 23 of the refrigeration apparatus is admitted through conduits 34 and 33 to the bellows 30. This causes an abnormal expansion of the bellows 30 which in turn operates the lever 23 to open the damper it to an extreme position which may be predetermined by a stop 48 for the lever 28. The wide open damper it allows for maximum by-pass of air through the passage ll until the refrigeration apparatus can reduce the temperature of the cooling element It so that the humidity require: ment of the humidostat 33 is satisfied. Thereupon, the humidostat will return to its normal position and operation continue'as previously described.

It will be understood that instead of a humidostat 33 I may employ a thermostat and reverse the action of the damper mechanism with respect to the operation of the bellows 30. This results in opening of the by-pass damper it when the air temperature is below normal and closing of the-damper when normal temperatures are restored. It will also be understood that the control humidostat 33 or thermostat may be located in a space such as a room to be conditioned instead of in thesupply duct as indicated. I may also employ a fixed orifice or capillary tube in place of the normally open valve 31 and thereby eliminate the need of a third point on the humidistat or thermostat.

It will be understood that various changes may be made within the scope of my invention which is therefore not limited to that which is shown in the drawing and described in the specification but only as indicated in the following claims.

What is claimed is:

1. In combination, means for conditioning air including a refrigeration apparatus having high and low pressure sides, pressure responsive means for regulating relative flow of air to be conditioned with respect to said conditioning means, and means for selectively connecting said pressure responsive means to the high and low pressure sides of said apparatus.

2. In combination, means for conditioning air including a-refrigeration apparatus having high and low pressure sides, pressure responsive means for regulating relative flow of air to be conditioned with respect to said conditioning means and connected to the low pressure side of said apparatus, and means for connecting said pressure responsive means to the high pressure side of said apparatus responsive to an abnormal air including an expansible bellows, a conduit 'connecting said bellows to the low pressure side of said refrigeration apparatus, a conduit connecting said bellows to the high pressure side of said apparatus, a solenoid operated valve in each of said conduits connecting the bellows to said refrigeration apparatus, and a three point psychrometric instrument arranged in the path of flow of air beyond said cooling element and arranged to selectively connect said solenoid operated valves to a source of electricity.

4. In combination, refrigeration apparatus having high and low pressure sides and including a cooling element, means forming a path of flow for air in contact with said cooling element and'a bypass passage for flow of air around said cooling element, a damper for regulating flow: of air through said by-pass passage, pressure responsive means for operating said damper and including an expansible bellows, a conduit connecting said bellows to the low pressure side of said refrigeration apparatus, a conduit connecting said bellows to the high pressure side of said apparatus, a solenoid operated valve in said conduit connecting the bellows to the high pressure side of said refrigeration apparatus, and an air condition re-'- sponsive device in the path of flow of air beyond said cooling element and arranged to connect said solenoid operated valve to a source of electricity.

5. In combination, refrigeration apparatus having high and low pressure sides and including a cooling element,,means forming a path of flow for air in contact with said cooling element and a by-pass passage for flow of air around said cooling element, a damper for regulating flow of air through said by-pass passage, pressure responsive means for operating said damper and including an expansible bellows, a conduit connecting said bellows to the low pressure side of said refrigeration'apparatus, a conduit connecting said bellows to the high pressure side of said apparatus, a valve in each of said conduits connecting the bellows to said refrigeration apparatus, and an air condition responsive device in the path of flow of air beyond. said cooling element and arranged to selectively operate said valves.

6,, In combination, means forming a conduit for flow of air, a blower forcausing flow of air through said conduit, refrigeration apparatus having high and low pressure sides and including a cooling element in said conduit, means forming a by-pass passage for flow of air around said cooling element, a damper for regulating flow of air through said by-pass passage, pressure responsive means for operating said damper, and an air condition responsive device in the path of flow of air beyond said cooling element and arranged to selectively connect said pressure responsive means to the high and low pressure sides of said apparatus.

7. In combination, means forming a conduit for flow of air, a blower for causing flow of air through said conduit, refrigeration apparatus having high and low pressure sides and including a cooling element in said conduit, means forming a by-pass passage for flow of air around said cooling element, a damper for regulating flow of air through said by-pass passage, and pressure responsive means for operating said damper and connected to the low pressure side of said refrigeration apparatus.

8. In combination, means forming a conduit for flow of air, a blower for causing flow of air through said conduit, refrigeration apparatus having high and low pressure sides and including a cooling element in said conduit, means forming a by-pass passage for flow of air around said cooling element, a damper for regulating flow of air through said by-pass passage, pressure responsive means for operating said damper connected to the low pressure side of said refrigeration apparatus, and means to connect said pressure responsive means to the high pressure side of said apparatus responsive to an abnormal air condition.

9. Apparatus for conditioning air including a refrigeration system comprising members forming a circuit for refrigerant fluid, a device for regulating flow of air to be attempered by said system, and a pressure actuated device having movement through distances functionally related to changes in pressure and connected to operate said air regulating device, said pressure device being connected to said circuit so as to be subjected to pressure therein. V

10. Apparatus for conditioning air including a refrigeration system comprising members forming a circuit for refrigerant fluid and devices for maintaining one part of said circuit at a higher pressure than the other part of said circuit, a device for regulating flow of air to beattempered by said system, and a pressure actuated device having movement through'distances functionally related to changes in pressure and connected to operate said control device, said pressure device being connected to the low pressure part of said circuit so as to be subjected to the pressure therein.

11. A method of conditioning air which includes circulating refrigerant fluid in a closed circuit in a manner so that the fluid is evaporated to produce a cooling effect in one part of the circuit, subjecting air to the cooling effect, and regulating the air subjected to the cooling effect by amounts functionally related in changes in force Within said circuit. a

12. A method of conditioning air which includes condensing refrigerant fluid at a certain pressure, evaporating the condensed fluid at a lower, pressure to produce a cooling effect, subjecting air to said cooling effect, and regulating the air subjected to said cooling effect by amounts functionally related to changes in said lower pressure.

13. Apparatus for cooling fluid including members forming a circuit for refrigerant fluid, a

device for regulating flow of fluid to be cooled by a portion of said circuit, and a pressure actuated device having movement through distances functionally related to changes in pressure and connected to operate said regulating device, said pressure device being connected to said circuit so as to be subjected to pressure therein.

14. Apparatus for cooling fluid including mempressure responsive device being connected to the low pressure part of said circuit so as to be subjected to the pressure therein.

WILLIAM J. AULSEBROOK. 

